Bioactive three loop coil

ABSTRACT

One aspect of the present invention pertains to an implantable medical device for at least partially obstructing a neck portion of a vascular aneurysm. The implantable medical device includes an occlusion subassembly having a central tubular member and at least one lateral protrusion fixedly attached to the central tubular member. The lateral protrusion(s) and the central tubular member are of a size and overall flexibility to lodge at the neck portion of the vascular aneurysm. A coil is attached to the lateral protrusion.

RELATED APPLICATIONS

[0001] This is a continuation-in-part of pending U.S. application Ser.No. 09/828,452, filed on Apr. 6, 2001, which is a continuation-in-partof U.S. application Ser. No. 09/352,188, filed on Jul. 12, 1999, nowU.S. Pat. No. 6,231,590, which is a continuation-in-part of U.S.application Ser. No. 09/189,540 filed on Nov. 10, 1998, now U.S. Pat.No. 6,187,024.

BACKGROUND OF THE INVENTION

[0002] The present invention deals with implantable medical devices.While conceivably the devices could be utilized in the context of avariety of body spaces, the present description, for the sake ofbrevity, will often be described in the context of the treatment ofvascular aneurysms. Accordingly, one aspect of the present inventiondeals with an implantable medical device for at least partiallyobstructing the neck portion of a vascular aneurysm.

[0003] Another aspect of the present invention pertains to a medicaldevice for forming an embolism within the vasculature of a patient. Moreparticularly, it is a vaso-occlusion device at least partially coatedwith a bioactive agent, an absorbable material or biopolymer or anabsorbable or biopolymer coating optionally containing or coated withother bioactive agents. A highly flexible vaso-occlusive device coatedwith such materials also forms a variation of the invention.

[0004] Vascular aneurysms are typically formed due to a weakening in thewalls of an artery. Often aneurysms are the site of internal bleedingand, catastrophically, the site of strokes. Different implantablemedical devices have been developed for treating vascular aneurysms.Treatments commonly known as “artificial vaso-occlusion” treatments areknown to be useful in treating aneurysms by filling associatedundesirable vascular spaces. A variety of different vaso-occlusivedevices are known to be at least arguably effective for the treatment ofaneurysms.

[0005] Vaso-occlusive devices are surgical implants that are placedwithin open sites in the vasculature of the human body. The devices areintroduced typically via a catheter to the site within the vasculaturethat is to be closed. That site may be within the lumen of a bloodvessel or perhaps within an aneurysm stemming from a blood vessel.

[0006] There are a variety of materials and devices that have been usedto create emboli in the vasculature of the human body. For instance,injectable fluids such as microfibrillar collagen, various polymericfoams and beads have been used. Certain injectable fluid devices can beintroduced through a catheter and are capable of forming a solidspace-filling mass in a target location. Polymeric resins, particularlycyanoacrylate resins, have been used as injectable vaso-occlusivematerials. Both the injectable gel and resin materials are typicallymixed with a radio-opaque material to allow accurate setting of theresulted materials. Although some of these agents provide for excellentshort-term occlusion, many are thought to allow vessel recanalizationdue to absorption of the agents into the blood. In addition, there aresignificant risks involved in use of cyanocrylates, and similarmaterials, due to the potential for misplacement. Such misplacement cancreate emboli in undesired areas. Generally, injectable fluid occlusiondevices are somewhat difficult, if not impossible, to retrieve once theyare improperly placed.

[0007] In some instances, materials such as hog hair and suspensions ofmetal particles have been introduced into an aneurysm by those wishingto form occlusions. It is believed that these materials encouragenatural cell growth within the sac portion of an aneurysm.

[0008] Several patents describe different deployable vaso-occlusivedevices that have added materials designed to increase theirthrombogenicity. For example, fibered vaso-occlusive devices have beendescribed in a variety of patents assigned to Target Therapeutics, Inc.,of Fremont, Calif. Vaso-occlusive coils having attached fibers are shownin U.S. Pat. Nos. 5,226,911 and 5,304,194, both to Chee et al. Anothervaso-occlusive coil having attached fiberous materials is found in U.S.Pat. No. 5,382,259, to Phelps et al. The Phelps et al. patent describesa vaso-occlusive coil which is covered with a polymeric fiberous braidon its exterior surface. U.S. Pat. No. 5,658,308, to Snyder, is directedto a vaso-occlusive coil having a bioactive core.

[0009] To further increase occlusive properties and thrombogenicity, avariety of vaso-occlusive devices have been treated with a variety ofsubstances. For instance, U.S. Pat. No. 4,994,069, to Ritchart et al.,describes a vaso-occlusive coil that assumes a linear helicalconfiguration when stretched and a folded, convoluted configuration whenrelaxed. The stretched condition is used in placing the coil at thedesired site (via passage through the catheter) and the coil assumes arelaxed configuration—which is better suited to occlude the vessel—oncethe device is so-placed. Ritchart et al. describes a variety of shapes.The secondary shapes of the disclosed coils include “flower” shapes anddouble vortices. The coils may be coated with agarose, collagen, orsugar.

[0010] U.S. Pat. No. 5,669,931, to Kupiecki, discloses coils that may befilled or coated with thrombotic or medicinal material. U.S. Pat. No.5,749,894, to Engelson, discloses polymer-coated vaso-occlusion devices.U.S. Pat. No. 5,690,671 to McGurk discloses an embolic element which mayinclude a coating, such as collagen, on the filament surface.

[0011] U.S. Pat. No. 5,536,274 to Neuss shows a spiral implant which mayassume a variety of secondary shapes. Some complex shapes can be formedby interconnecting two or more of the spiral-shaped implants. To promoteblood coagulation, the implants may be coated with metal particles,silicone, PTFE, rubber lattices, or polymers.

[0012] As has been alluded to above, advancements in the artificialocclusion of aneurysms have occurred due to the delivery andimplantation of metal coils as vaso-occlusive devices.

[0013] Vaso-occlusion coils are generally constructed of a wire, usuallymade of a metal or metal alloy, which is wound into a helix. Mostcommonly, these coils are introduced in a stretched linear form througha catheter to the selected target site, such as a particular aneurysm.The vaso-occlusion coils typically assume an irregular shape upondischarge of the device from the distal end of the catheter. The coilsmay undertake any of a number of random configurations used to fill ananeurysm. In some instances, vaso-occlusion coils are adapted to assumea predetermined secondary shape designed to enhance the ability to fillundesirable vascular spaces.

[0014] A variety of vaso-occlusion coils and braids are known. Tungsten,platinum, and gold threads or wires are said to be preferred.Vaso-occlusion coils have a variety of benefits including that they arerelatively permanent, they may be easily imaged radiographically, theymay be located at a well defined vessel site, and they can be retrieved.

[0015] In some instances, particularized features of coil designs, suchas specialized mechanisms for delivering vaso-occlusion coils throughdelivery catheters and implanting them in a desired occlusion site, havebeen described. Examples of categories of vaso-occlusion coils havingspecialized delivery mechanisms include pushable coils, mechanicallydetachable coils, and electrolytically detachable coils.

[0016] Pushable coils are commonly provided in a cartridge and arepushed or plunged from an engaged delivery catheter into an aneurysm. Apusher wire advances the pushable coils through and out of the deliverycatheter into the site for occlusion.

[0017] Mechanically detachable vaso-occlusive devices are typicallyintegrated with a pusher wire and are mechanically detached from thedistal end of that pusher wire after exiting a delivery catheter.

[0018] A variety of mechanically detachable devices are also known. Forinstance, U.S. Pat. No. 5,234,437, to Sepetka, shows a method ofunscrewing a helically wound coil from a pusher having an interlockingsurface. U.S. Pat. No. 5,250,071, to Palermo, shows an embolic coilassembly using interlocking clasps that are mounted both on the pusherand on the embolic coil. U.S. Pat. No. 5,261,195, to Twyford et al.,shows a pusher-vaso-occlusive coil assembly having an affixed,proximately extending wire carrying a ball on its proximal end and apusher having a similar end. The two ends are interlocked and disengagedwhen expelled from the distal tip of the catheter. U.S. Pat. No.5,312,415, to Palermo, also shows a method for discharging numerouscoils from a single pusher by use of a guidewire which has a sectioncapable of interconnecting with the interior of the helically woundcoil. U.S. Pat. No. 5,350,297, to Palermo et al., shows a pusher havinga throat at its distal end and a pusher through its axis. The pushersheath will hold onto the end of an embolic coil and will then bereleased upon pushing the axially placed pusher wire against the memberfound on the proximal end of the vaso-occlusive coil.

[0019] Within electrolytically detachable vaso-occlusive devices, thevaso-occlusive portion of the assembly is attached to a pusher wire viaa small electrolytically severable joint. The electrolytically severablejoint is severed by the placement of an appropriate voltage on the corewire. The joint erodes in preference either to the vaso-occlusive deviceitself or to the pusher wire. In accordance with principles ofcompetitive erosion, parts of the wire that are not intended to erodeare often simply insulated to prevent such an electrolytic responsecaused by the imposition of the electrical current.

[0020] U.S. Pat. No. 5,354,295 and its parent 5,122,136, both toGuglielmi et al., describe an electrolytically detachable embolicdevice. That is to say that a joint between the pusher wire and thevaso-occlusive portion dissolves or erodes when an electrical current isapplied to the pusher wire.

[0021] Some vaso-occlusive devices include specialized mechanicalfeatures and/or shapes. Various shaped coils have been described. Forexample, U.S. Pat. No. 5,624,461, to Mariant, describes athree-dimensional in-filling vaso-occlusive coil. U.S. Pat. No.5,639,277, to Mariant et al., describes embolic coils having twistedhelical shapes and U.S. Pat. No. 5,649,949, to Wallace et al., describesvariable cross-section conical vaso-occlusive coils. A random shape isdescribed, as well. U.S. Pat. No. 5,648,082, to Sung et al., describesmethods for treating arrhythmia using coils which assume randomconfigurations upon deployment from a catheter. U.S. Pat. No. 5,537,338describes a multi-element intravascular occlusion device in which shapedcoils may be employed. Spherical shaped occlusive devices are describedin U.S. Pat. No. 5,645,558 to Horton. Horton describes how one or morestrands can be wound to form a substantially hollow spherical or ovoidshape when deployed in a vessel. U.S. Pat. Nos. 5,690,666 and 5,718,711,by Berenstein et al., show a very flexible vaso-occlusive coil havinglittle or no shape after introduction into the vascular space.

[0022] One type of aneurysm commonly known as a “wide-neck aneurysm” isknown to present particular difficulty in the placement and retention ofvaso-occlusive devices. Furthermore, vaso-occlusive devices, inparticular, vaso-occlusion coils, lacking substantial secondary shapestrength may be difficult to maintain in position within an aneurysm nomatter how skillfully they are placed.

[0023] Vaso-occlusive devices are typically placed in an aneurysm in thefollowing fashion. A micro-catheter is initially steered into oradjacent the entrance of an aneurysm, typically aided by the use of asteerable guide wire. The guide wire is then withdrawn from themicro-catheter and replaced by the vaso-occlusive device. Thevaso-occlusive device is advanced through and out of the micro-catheter,desirably being completely delivered into the aneurysm. After, orperhaps, during, delivery of the device into the aneurysm, there is aspecific risk that the device or a portion of the device might migrateout of the aneurysm entrance zone and into the feeding vessel. Thepresence of the device in the feeding vessel may cause the undesirableresponse of an occlusion in the feeding vessel. Also, there is aquantifiable risk that blood flow in the feeding vessel and the aneurysmmay induce movement of the device further out of the aneurysm, resultingin a more developed embolus in the patent vessel.

[0024] As noted above, aneurysms present particularly acute medical riskdue to the dangers associated with an inherently thin vascular wall. Theutilization of vaso-occlusive devices to occlude an aneurysm withoutoccluding the adjacent vasculature poses a special challenge. Methodsthat meet this challenge and still avoid undue risk of an aneurysmrupture are desirable. None of the above documents discussvaso-occlusive devices such as those found below.

SUMMARY OF THE INVENTION

[0025] One aspect of the present invention pertains to an implantablemedical device for at least partially obstructing a neck portion of avascular aneurysm. The implantable medical device includes an occlusionsubassembly having a central tubular member and at least one lateralprotrusion fixedly attached to the central tubular member. The lateralprotrusion(s) and the central tubular member are of a size and overallflexibility to lodge at the neck portion of the vascular aneurysm. Acylindrical helical coil is attached to the lateral protrusion.

[0026] Another aspect of the present invention pertains to anotherimplantable medical device. The implantable medical device includes aloop of wire having first and second ends connected to a base member. Acylindrical helical coil is radially disposed about a portion of theloop of wire. A material for encouraging a cellular response is disposedon at least one portion of the coil. The material for encouraging thecellular response is also biodegradable.

[0027] Still another aspect of the present invention pertains to anotherimplantable medical device. The medical device includes a loop of wirehaving first and second ends connected to a base member. A cylindricalhelical coil is radially disposed about a portion of the loop of wire. Afiberous woven tubular member coaxially engages at least one portion ofthe cylindrical helical coil.

BRIEF DESCRIPTION OF THE DRAWINGS

[0028]FIG. 1 is a partial sectioned view of a catheter extending towardan aneurysm emanating from the wall of a blood vessel.

[0029]FIG. 2 is a side view of an implantable bridge assembly.

[0030]FIG. 3 is a partial sectioned view of the implantable bridgeassembly inserted within the catheter.

[0031]FIG. 4 is a partial sectioned view of the implantable bridgeassembly.

[0032]FIG. 5 is an end view, taken along line 2A in FIG. 2, of theimplantable bridge assembly.

[0033]FIG. 6 is a detailed end view of a lateral protrusion portion ofthe implantable bridge assembly.

[0034]FIGS. 7A to 7F are partial sectioned views of the aneurysm andillustrate procedural elements associated with using the implantablebridge assembly.

[0035]FIG. 8 is a perspective view of one embodiment of the invention.

[0036]FIG. 9 is a perspective view of another embodiment of theinvention showing a coil having a permanently bonded inner coating of athrombotic agent and a water-soluble, dissolvable outer coating of ananti-thrombotic agent.

[0037]FIG. 10 is a detailed end view of a lateral protrusion portion ofthe implantable bridge assembly in accordance with another embodiment ofthe present invention.

[0038]FIG. 11 is a detailed end view of a lateral protrusion portion ofthe implantable bridge assembly in accordance with another embodiment ofthe present invention.

DETAILED DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENTS

[0039]FIG. 1 illustrates a partial sectioned view of an aneurysm 100emanating from the wall of a feeding vessel 105. A catheter 110 is shownhaving a radio-opaque band 115 at its distal end. As is known in theart, radio-opaque band 115 assists in the guidance of catheter 110through a vascular system utilizing principles of radiography orfluoroscopy. As illustrated, the distal end of catheter 110 has beenguided so as to extend through a neck portion 120 of aneurysm 100.

[0040]FIG. 2 illustrates a side view of an implantable retainer bridgeassembly 200 in accordance with one aspect of the present invention.Assembly 200 includes a plurality of lateral protrusions 205, which arefixedly connected to a base section 210. In accordance with oneembodiment, base section 210 is a central tubular member. Lateralprotrusions 205 in combination with base section 210 make up a bridgesubassembly 202. While lateral protrusions 205 are illustratively wireloops, other types of lateral protrusions should be considered withinthe scope of the present invention. For example, lateral protrusions 205could be formed as a plurality of non-looping arms extending from basesection 210. In addition, while FIG. 2 illustratively includes threelateral protrusions 205, more or fewer lateral protrusions could beutilized.

[0041] Retainer assembly 200 further includes a core wire 215 (also knowas a pusher wire) having a distal end 220 which includes a severablejoint 225. Bridge subassembly 202, more particularly, base section 210,is fixedly connected to distal end 220 of core wire 215 and ispositioned just distally of severable joint 225. In accordance with oneembodiment, as will be described below, the bridge subassembly isdirectly connected to a portion of severable joint 225.

[0042] Retainer assembly 200 is deliverable through a tubular membersuch as catheter 110 in FIG. 1. The shape of retainer assembly 200 shownin FIG. 2 is the secondary shape or deployed shape found after theassembly has been pushed from a distal end of catheter 110. As retainerassembly 200 is pushed through catheter 110, it generally has arelatively retracted or low profile shape, which can be referred to asthe delivery shape or primary shape. The delivery shape is essentiallythe shape of the interior of catheter 110.

[0043]FIG. 3 is an illustration of retainer assembly 200 in the deliveryshape, as it is being delivered through catheter 110. The same referencenumbers are used in FIG. 3 for elements that are the same or similar tothose elements illustrated in FIGS. 1 and 2. After deployment fromcatheter 110, retainer assembly 200 assumes its secondary shape as isseen in FIG. 2. To undergo such massive changes in shape, lateralprotrusions 205 are typically produced of material such as asuper-elastic alloy. Super-elastic and pseudo-elastic shape recoveryalloys and shape memory polymers (i.e., urethanes) are well known inthis art. These alloys are especially suitable for lateral protrusions205 because of their capacity to recover—almost completely—to an initialconfiguration once stress is removed. In addition to super-elastic andpseudo-elastic alloys, other materials having shape memorycharacteristics are within the scope of the present invention.

[0044] Severable joint 225 (FIGS. 2 and 3) may also be called asacrificial link. Severable joint 225 includes means for severing bridgesubassembly 202 from most, if not all, of core wire 215. In oneembodiment of the present invention, bridge subassembly 202 is directlyand fixedly connected to a distal portion of severable joint 225,enabling a complete severance of subassembly 202 from core wire 215. Inanother embodiment, subassembly 202 is fixedly connected to a smallportion of core wire 215 (distally located from joint 225) that remainswith subassembly 202 following severance of joint 225. For example, thesmall portion of core wire 215 might, following severance, besubstantially contained within base portion 210 of subassembly 202.

[0045] The severing action of joint 225, as will be described in greaterdetail below, enables subassembly 202 to remain in a portion of aneurysm100 (FIG. 1) after most or all of core wire 215 and catheter 110 havebeen removed from feeding vessel 105. In accordance with oneillustrative embodiment, severable joint 225 causes severance viamechanical means. Other means, however, should be considered within thescope of the present invention.

[0046] For the purpose of simplifying description, it will be assumedthat severable joint 225 is an electrolytic severable joint. It shouldbe noted that the Figures reflect this embodiment of the presentinvention. In accordance with the embodiment, as will be described ingreater detail in relation to FIG. 4, core wire 215 is coated with anelectrical insulator that is not susceptible to dissolution viaelectrolysis in blood or other ionic media. Severable joint 225 is notcoated with such insulator and is constructed of a material that issusceptible to electrolytic dissolution in blood. Severable joint 225 isalso significantly more susceptible to electrolytic dissolution thanbase section 210 and lateral protrusions 205 (bridge subassembly 202).In accordance with one embodiment, lateral protrusions 205 are attachedto base section 210 but are not in an electrically conductiverelationship therewith, and further, are coated with an electricalinsulator that is not susceptible to dissolution via electrolysis inblood or other ionic media. In accordance with one aspect of the presentinvention, in response to an electrolytic control signal, only severablejoint 225 dissolves, such that bridge subassembly 202 is severed fromcore wire 215. As was described above, subassembly 202 could be directlyconnected to a portion of severable joint 225 or, alternatively, basesection 210 of subassembly 202 could be fixedly connected to a smallportion of core wire 215 (distally located from joint 225) that remainswith subassembly 202 following severance of joint 225.

[0047]FIG. 4 is a partial sectional view of an embodiment of animplantable bridge assembly similar to the one illustrated in FIG. 2.The same reference numbers are used in FIG. 4 for elements that are thesame or similar to those illustrated in previously describedembodiments. It should be noted that the severable joint 225 within theFIG. 4 embodiment is illustratively consistent with the electrolyticseverance embodiment described above. As was previously mentioned, otherseverance methods could be utilized.

[0048] In FIG. 4, implantable bridge assembly 200 includes lateralprotrusions 205 that each illustratively include an attached marker coil400. Marker coils 400 are illustratively constructed of radio-opaquematerial (i.e., platinum) that assists in the guidance of bridgesubassembly 202 through a tubular delivery device (such as catheter 110in FIG. 1) and through a vascular system, utilizing principles ofradiography or fluoroscopy. In particular, marker coils 400 assist inthe positioning of bridge subassembly 202 within an aneurysm, such asaneurysm 100 (FIG. 1). Bridge assembly 200 also includes base section210 that comprises an outer marker coil 405 and an inner marker coil410. In accordance with illustrative embodiments of the presentinvention, either, neither or both of outer marker coil 405 and innermarker coil 410 could be constructed of a radio-opaque material. As waspreviously described, such material assists in the guidance ofsubassembly 202 through a vascular system and into a target aneurysm.

[0049] Continuing with the description of FIG. 4, lateral protrusions205 each illustratively include a plurality of ends 415 that are fixedlysecured between outer marker coil 405 and inner marker coil 410. Othermeans for securing lateral protrusions 205 to base section 210 should beconsidered within the scope of the present invention. Inner marker coil410 is adapted to radially surround and fixedly secure the most distalpoint of core wire 215. In another embodiment (not illustrated), as wasdescribed above, inner marker coil 410 could be adapted to fixedlyconnect to a distal portion of severable joint 225. In accordance withthe electrolytic severance embodiment of severable joint 225, core wire215 is covered with an insulation material 425 such that severable joint225 is the only completely exposed portion of core wire 215. As wasdiscussed above, this encourages the electrolytic severabilty ofseverable joint 225 when an electrolytic control signal is applied toassembly 200. Finally, retainer assembly 200 includes an optional markercoil 420 enclosed within insulation material 425. Optional marker coil420 is constructed of a radio-opaque material (i.e., platinum) toprovide further assistance in the location and precise placement ofbridge subassembly 202 within a vascular system, and to locate arelative position of subassembly 202 with respect to a deliverycatheter.

[0050]FIG. 5 is an end view of an embodiment of a bridge subassembly 202portion of an implantable bridge assembly 200 similar to thoseillustrated in FIGS. 2 and 4. The FIG. 5 end view represents a viewtaken along line 2A in FIG. 2. The same reference numbers are used inFIG. 5 for elements that are the same or similar to those elementsillustrated in previously described embodiments.

[0051] As is illustrated, retainer sub-assembly 202 includes lateralprotrusions 205, a base section 210 and distal end 220 of core wire 215.In accordance with another embodiment, as was described above, basesection 210 could alternatively be fixedly secured to a distal portionof a severable joint 225. Base section 210 further comprises innermarker coil 410 and outer marker coil 405. The plurality of ends 415associated with lateral protrusions 405 are illustratively fixedlysecured between outer marker coil 410 and inner marker coil 405.

[0052]FIG. 6 is an end view illustration of one particular lateralprotrusion 205, in accordance with an illustrative embodiment of thepresent invention. Any of the lateral protrusions 205 described inrelation to other embodiments of the present invention could beconfigured similar to the FIG. 6 embodiment described below. The samereference numbers are used in FIG. 6 for elements that are the same orsimilar to those illustrated in previously described embodiments.

[0053] Lateral protrusion 205 illustrated in FIG. 6 includes an interiorwire 610 having an attached marker coil 400. Details pertaining tomarker coil 400 were described above in relation to FIG. 4. Lateralprotrusion 205 further includes a suture material 600 wrapped or braidedaround a portion of interior wire 610 that is not covered by marker coil400. While FIG. 6 illustratively shows all of interior wire 610 coveredeither by marker coil 400 or suture material 600, some portions of wire610 could, in accordance with one embodiment of the present invention,be exposed. In addition, additional suture material 600 could, inaccordance with another embodiment, be attached to any portion of bridgesubassembly 202 (i.e., attached to inner coil 410 or outer coil 405).Suture material 600 could, in accordance with yet other embodiments,also be attached to the distal end 210 or to marker coils 400.

[0054] Suture material 600 is illustratively a therapeutic agent. Inaccordance with one embodiment, suture material 600 is or contains abioactive material, such as a drug, protein, or genetic material, usefulfor the medical treatment of an aneurysm or other medical disorder. Inaccordance with another embodiment, suture material 600 is a bioactivematerial of a different type, such as a material selected or designed toencourage cell growth within a vascular aneurysm. In accordance withthis embodiment, the material could illustratively be a naturalbio-material, such as collagen, gelatin, fibrin, fibronectin,fibrinogen, hyaluronic acid, polysaccharides, or proteoglycans, or anycombination thereof; or a combination of natural bio-materials andsynthetic absorbable materials. In accordance with another embodiment,suture material 600 is constructed of a material that encourages cellgrowth within a targeted portion of an aneurysm, and is biologicallyabsorbed by the human body. While there are many materials within thescope of the present invention that could be utilized as suture material600, two that are biologically absorbable and designed to encourage cellgrowth are polylactic acid (PLA) and polyglycolic acid (PGA). Inaccordance with one embodiment, a mixture or composite compositioncomprising PLA and PGA could be utilized. Other potential suturematerials that may encourage cell growth include polymers containing□-caprolactone, trimethylene carbonate, and p-dioxanone. The suturematerials presently listed are only examples of the many potentialmaterials that should be considered within the scope of the presentinvention.

[0055] Suture material 600 could be applied to any or all portions ofbridge subassembly 202 in accordance with a variety of methods, all ofwhich are embodiments of the present invention. Illustratively, suturematerial 600 is replaced by a material having a substantially liquidform which is sprayed on subassembly 202 or applied using a dip coatingprocedure. In that embodiment, the entire subassembly 202 can be coatedwith the therapeutic agent. Of course, suture material 600 or otherforms of the therapeutic agent can be applied to substantially anyportion of subassembly 202.

[0056] In addition, some materials suitable for use as suture material600 (such as polylactic acid, polyglycolic acid or a mixture thereof)are available in extruded or molded forms. Extruded or molded materialssuch as these can be formed into desired shapes and applied to anyportion of bridge subassembly 202. In accordance with one embodiment ofthe present invention, the material is formed into a tubular form andslipped over a portion of subassembly 202, such as over a portion of thewire forming a lateral protrusion 205. In accordance with anotherembodiment, as is illustrated in FIG. 6, the material is formed into asolid or strand form and is wrapped or braided around portions of bridgesubassembly 202. In accordance with yet another embodiment, the materialis heated and wrapped or braided around a mandrel having a desired shape(i.e., having a curvature consistent with a portion of subassembly 202).After the wrapped or braided material has cooled, it is removed from themandrel and then has a permanent relaxed shape convenient forapplication to a bridge subassembly 202.

[0057] FIGS. 7A-7F are a series of partial sectioned views of ananeurysm 100 emanating from the wall of a feeding vessel 105. The samereference numbers are used in FIGS. 7A-7F for elements that are the sameor similar to those illustrated in previously described embodiments.FIGS. 7A-7F illustrate procedural elements associated with using animplantable bridge assembly consistent with the present invention, ashas been described in relation to the above described illustrativeembodiments.

[0058] In accordance with the present invention, as is represented byFIG. 1, catheter 110 is initially steered into or adjacent to theentrance of an aneurysm, typically aided by the use of a steerable guidewire (not illustrated). As was discussed above in relation to FIG. 1,radio-opaque band 115 may be used to assist in the steering of catheter110 through a vascular system.

[0059] When catheter 110 has been positioned relative to an aneurysm,the guide wire is removed. As was discussed in relation to FIG. 3,implantable bridge assembly 200 is then pushed through catheter 110 sothat bridge subassembly 202 exits a distal end of catheter 110 and takeson a deployed shape (similar to FIG. 2) within aneurysm 100. FIG. 7Aillustrates subassembly 202 in the deployed shape within aneurysm 100.In accordance with the embodiment of FIG. 7A, subassembly 202 ispositioned such that lateral protrusions 205 extend into a sac portion700 of aneurysm 100.

[0060]FIG. 7B illustrates an alternate placement of a deployedsubassembly 202 within an aneurysm 100. In accordance with the FIG. 7Bembodiment of the present invention, subassembly 202 is positioned suchthat lateral protrusions 205 engage neck portion 120 of aneurysm 100.Depending on characteristics of the aneurysm being treated, particularlydepending on the size of neck portion 120, either of the embodimentsillustrated in FIGS. 7A and 7B may be most appropriate.

[0061] It should be noted that marker coil devices, such as marker coils400, inner coil 410, outer coil 405 and optional coil 420, describedabove in relation to FIG. 4 could be utilized to steer and positionsubassembly 202 with an aneurysm. In accordance with an embodiment ofthe present invention, any or all of these radio-opaque markers could beutilized by an operator of the present implantable medical device toprovide steering capability utilizing principles of radiography orfluoroscopy.

[0062] After bridge subassembly 202 is placed within a portion ofaneurysm 100, the next step is to sever the subassembly from pusher wire215. This severance occurs as described above in relation to thedescription of severable joint 225. In accordance with one embodiment,severable joint 225 dissolves in response to an electrolytic signalbeing applied thereto, thereby disengaging subassembly 202 from all ormost of core wire 215. FIG. 7C is an illustration of bridge subassembly202 engaged within aneurysm 100 after joint 225 has been severed.

[0063] After joint 225 has been severed, core wire 215 is removed fromcatheter 110. In accordance with one embodiment of the presentinvention, catheter 110 is then withdrawn, leaving subassembly 202bridging neck 120 of aneurysm 100. As was described in relation to FIG.6, in accordance with one embodiment of the present invention,subassembly 202 includes an attached suture material or other form thatserves as a therapeutic agent for the treatment of aneurysm 100. Inaccordance with one embodiment, as was described above, the therapeuticagent is a biologically absorbable material that encourages cell growthin the neck 120 portion of aneurysm 100 and is biologically absorbed.Accordingly, subassembly 202 is capable of serving as a device for atleast partially obstructing the neck 120 portion of an aneurysm. Inaccordance with another embodiment, as was also described above, thesuture material on subassembly 202 simply serves as a drug deliveryagent.

[0064] In accordance with one aspect of the present invention, bridgesubassembly 202 can be utilized to retain vaso-occlusive devices, suchas vaso-occlusion coils, within an aneurysm. Accordingly, as isillustrated in FIG. 7D, after core wire 215 has been removed fromcatheter 110, the distal end of catheter 110 is then engaged with anopening in bridge subassembly 202. Next, vaso-occlusive devices,illustratively vaso-occlusion coils 705, are pushed through catheter 110into aneurysm 100. Then, as is illustrated by FIG. 7E, catheter 110 isremoved from feeding vessel 105 and subsequently from the vascularsystem. Of course, in accordance with another embodiment of the presentinvention, coils 705 can be placed in the aneurysm 100 through aseparate delivery catheter after placing subassembly 202 but prior todetaching it. FIG. 7F is an illustration of this latter embodimentwherein coils 705 are transported through a catheter 710 that isindependent of catheter 110.

[0065] Regardless of the method of implantation, the implantedsubassembly 202 illustratively includes an attached suture material thatencourages cell growth in the neck 120 portion of aneurysm 100.Accordingly, subassembly 202, in combination with the attached suturematerial, serves as a retaining device for retaining vaso-occlusioncoils 705 within aneurysm 100. In accordance with one embodiment, asdescribed above, the suture material is biologically absorbable. Inaccordance with another embodiment of the present invention,vaso-occlusive devices are delivered before severance of severable joint225 through a catheter 710 or 110 and through an opening within basesection 210 of bridge subassembly 202.

[0066] Another aspect of the present invention pertains to avaso-occlusive device having an outer coating of a collagen-basedmaterial or other bioactive material. It may have other functionaldrugs, genetic material, or proteins associated (chemically linked orphysically mixed) with the collagen. The collagen-based material is forthe purpose of enhancing the rate and density of the occlusion producedby the vaso-occlusive device at the selected body site and specificallyto promote permanent cellular in-growth at that site. The therapeutics,drugs, genetic material, or proteinaceous material associated with thecollagenous material are placed in the collagen to provide specificeffects outlined below.

[0067] As used, the outer, collagen-based or other bioactive-basedcoating is preferably placed over an inner tie layer coating ortreatment. The binding layer preferably provides a layer contiguous tothe vaso-occlusive device and the outer coating. The inner coating isgenerally bonded to the vaso-occlusive member. The inner coating may beof known silane coupling agents or primer polymer agents (e.g., lowmolecular weight polymer adhesives) or the like. The inner coating mayalso be deposited on the member by plasma treatment or may simply be aplasma treatment of the type intended to etch the substrate. The innercoating may also include vapor-deposited polymers, e.g., polyxyxyleneand the like. Other methods for applying the thin polymeric innercoating, e.g., by dripping or spraying dilute polymeric solution, mayalso be employed.

[0068] Preferably, the inner coating is permanently bonded to the coiland either chemically or physically bonded to the outer coating so thatshortly after coil deployment, the outer material can safely perform itsintended purposes, i.e. beginning the healing cascade within the vessel.

[0069] Another suitable tie layer coating involves “plasma treatment” ofcoils. (See, e.g., co-pending U.S. Ser. No. 08/598,325). Theseplasma-treated coils exhibit an amino-functionality which may bemeasured using known chemical methods. When the devices treated by thisprocess are placed in the bloodstream, the amino-functionality resultsin a slight positive ionic charge on the surface of the fibers. Thisamino-functionality attracts platelets and thrombogenic proteins fromthe bloodstream. Plasma treatment may be carried out using e.g., aplasma generator such as that found in U.S. Pat. No. 3,847,652. Theplasma may comprise a nitrogen-containing gas, preferably thosecontaining diatomic nitrogen or ammonia. Gas pressures areadvantageously maintained at a very low level, e.g., no greater thanabout 5 millimeters of mercury, preferably from 0.1 to 2 millimeters ofmercury.

[0070] The period of time in which the vaso-occlusive device issubjected to the plasma need not be great. That is to say that for mostapplied power settings below about 200 watts and in the radio frequencyregion between 1 and 50 megahertz, the time of reaction need not begreater than 10 minutes to achieve the results described herein.

[0071] Other plasma treating steps which are intended to etch thesubstrate are also suitable for this invention.

[0072]FIGS. 8 and 9 show typical vaso-occlusive devices suitable for usewith this procedure. FIG. 8 shows a typical vaso-occlusive device 1100.Vaso-occlusive device 1100 is shown in FIG. 8 to include a helicallywound coil 1102 having tips 1104 to ease the potential of the componentwire to cause trauma in a blood vessel. The device may include tufts orfiber bundles attached to it, so as to increase the amount and volume offiber held by the coil and thereby to promote overall thrombogenicity ofthe device. Typical of a vaso-occlusive device comprising a helical coilhaving attached fiberous elements such as shown in FIG. 8 is found inU.S. Pat. No. 5,226,911, to Chee et al., the entirety of which isincorporated by reference.

[0073]FIG. 9 shows a vaso-occlusive device 1200 comprising a helicallywound coil 1202, an inner tie coating 1204 and an outer collagenouscoating 1206. The inner coating is generally a substance, preferablyproteinaceous, which is bound to the coil 1202 and which is also bound,physically or chemically, to the outer collagenous covering 1206.

[0074] The occlusion devices of the invention may be made usingconventional equipment and procedures. For example, helical coils may beprepared by wrapping a suitable wire about a cylindrical or conicalmandrel. The strand(s) are then placed axially through the core of thehelix and, if a multiplicity of strands are employed, their ends may bebound by heat, adhesives, or mechanical means. Radial filaments may beattached to the windings of the helix by tying or with adhesives.

[0075] The polymeric materials used in the vaso-occlusive devices inFIG. 8 and FIG. 9 are known materials. They are those materials whichare generally approved for use as implants in the body or could be soapproved. They may be of polymers such as polyethylene, polypropylene,polyvinylchloride, polyamides such as Nylon, polyurethanes,polyvinylpyrrolidone, polyvinyl alchohols, polyvinylacetate, celluloseacetate, polystyrene, polytetrafluoroethylene, polyesters such aspolyethylene terephthalate (Dacron), silk, cotton, and the like. Whenthe polymers are fiberous, they are often looped or tufted as shown inthe drawings. Although it is not critical to this invention, they areusually assembled in bundles of 5 to 100 fibers per bundle. Preferredmaterials for the polymer component of vaso-occlusive devices comprisepolyesters, polyethers, polyamides, and polyfluorocarbons. Especiallypreferred is polyethyleneterephthalate, sold as Dacron. Placing aprotein-based covering on the fibers is a variation of the invention.

[0076] Another variation of the invention includes the specific use ofpolymers which evince an angiogenic response, preferably, biodegradablepolymers, that are associated with the vaso-occlusive support base. By“associated” is meant that the material is tied to or is made to adhereto the vaso-occlusive support base. The composition may be a fabric orgauze-like structure. It may also be a non-woven or loose agglomerationof individual fibers. In general, they need to stay in place during theplacement of the device in the body.

[0077] Preferably, the associated covering is a polymeric material suchas a biodegradable polymer, e.g., polyglycolic acid, polylactic acid,reconstituted collagen, poly-p-dioxanone, and their copolymers such aspoly(glycolide-lactide) copolymer, poly(glycolide-trimethylenecarbonate) coploymer, poly(glycolide-ε-caprolactone) copolymer,glycolide-trimethylene carbonate triblock copolymer, and the like.Mixtures of the noted polymers, e.g., of polylactide and polyglycolidemay also be used. The associated coverings may also be used inconjunction with the bioactive coatings discussed elsewhere.

[0078] The coils (1102 in FIG. 8 and 1202 in FIG. 9) may be made of anyof a wide variety of biocompatible metals or polymers or carbon. Inparticular, the metals may be selected from gold, rhenium, platinum,palladium, rhodium, ruthenium, various stainless steels, tungsten, andtheir alloys, titanium/nickel alloys particularly nitinoltype alloys.The preferred alloy is one comprising upwards of 90 percent platinum andat least a portion of the remainder, tungsten. This alloy exhibitsexcellent biocompatibility and yet has sufficient strength and ductilityto be wound into coils of primary and secondary shape and will retainthose shapes upon placement of the vaso-occlusive device in the humanbody. The diameter of the wire typically making up the coils is often ina range of 0.005 and 0.050 inches. The resulting primary coil diametertypically is in the range of 0.008 and 0.085 inches. Smaller coildiameters are used for finer problems and larger coil diameters and wirediameters are used in larger openings in the human body. A typical coilprimary diameter is 0.015 and 0.018 inches. The axial length of avaso-occlusive device may be between 0.5 and 100 centimeters. The coilsare typically wound to have between 10 and 75 turns per centimeter.

[0079] In addition to the coils shown in the Figures, the vaso-occlusivedevice may comprise a substrate comprising a woven braid rather than thehelical coil shown in those Figures. The vaso-occlusive device maycomprise a mixture of the coil and braid. Indeed, it is within the scopeof this invention that a portion of the coil be polymeric or acombination of metal and polymer.

[0080] It is further within the scope of this invention that thevaso-occlusive device comprise shapes or structures other than coils orbraids, for example, spherical structures and the like.

[0081] In one aspect of the present invention, the vaso-occlusivedevices described above and those similar to those specificallydescribed above, are first optionally treated with a tie layer coatingand then subjected to treatment to provide the outer collagenous,proteinaceous, or bioactive material layer. Preferably, neither theinner nor outer coating interfere with the shape of the coil afterdeployment. In one variation of the invention, the outer layer isapplied to the vaso-occlusive base without the inner tie layer, but isapplied in such an amount that the resulting assembly is notsignificantly more stiff than is the vaso-occlusive device without thecovering. That is to say, the coated device is not more than 35%,preferably not more than 15%, and most preferably not more than 5%,stiffer than is the untreated device base. Preferably, the covering isless than about 1.0 mil, more preferably less than about 0.5 mil inthickness.

[0082] When a collagen layer, the outer collagenous layer may be of awide variety of types, natural or synthetic, but preferably comprises aphot-polymerizable collagen which will bind both with the inner tielayer and with the added bioactive agents. The preferred collagenousmaterials have the same surface functional groups as to Type I and TypeIV natural collagens. Those functional groups are typically of the typewhich bind to acrylate-type linkages.

[0083] The outer collagenous or proteinaceous coating may furthercontain additional materials which have one or more functions,including, but not limited to, reducing friction, providing atherapeutic for local or blood borne delivery, or enhancing thrombosis,coagulation, or platelet activity. The additional materials may beapplied either as a substantially pure layer over the collagenous layeror chemically bonded to (and interspersed with) the collagenous layer orphysically bonded to the outer collagenous layer. The added bioactivematerials may be, e.g., genes, growth factors, biomolecules, peptides,oligonucleodites, members of the integrin family, RGD-containingsequences, oligopeptides, e.g., fibronectin, laminin, vitronectin,hyaluronic acid, silk-elastin, fibrogenin, and other basement membraneproteins with bioactive agents.

[0084] Non-limiting examples of bioactive coating or materials suitablein this invention include both natural and synthetic compounds, e.g.,fibrinogen, other plasma proteins, growth factors (e.g., vascularendothelial growth factor, “VEGF”), synthetic peptides of these andother proteins having attached RGD (arginine-glycine-aspartic acid)residues generally at one or both termini, or other cell adhesionpeptides, i.e., GRGDY, oligonucleodides, full or partial DNA constructs,natural or synthetic phospholipids, or polymers with phosphorylcholinefunctionality.

[0085] Other bioactive materials which may be used in the presentinvention include, for example, pharmaceutically active compounds,proteins, oligonucleotides, ribozymes, anti-sense genes, DNA compactingagents, gene/vector systems (i.e., anything that allows for the uptakeand expression of nucleic acids), nucleic acids (including, for example,naked DNA, cDNA, RNA, DNA, cDNA, or RNA in a non-infectious vector or ina viral vector which may have attached peptide targeting sequences;antisense nucleic acid (RNA or DNA); and DNA chimeras which include genesequences and encoding for ferry proteins such as membrane translocatingsequences (“MTS”) and herpes simplex virus-1 (“VP22”)), and viral,liposomes and cationic polymers that are selected from a number of typesdepending on the desired application, including retrovirus, adenovirus,adeno-associated virus, herpes simplex virus, and the like. For example,biologically active solutes include anti-thrombogenic agents such asheparin, heparin derivatives, urokinase, PPACK (dextrophenylalanineproline arginine chloromethylketone), rapamycine, probucol, andverapimil; angiogenic and anti-angiogenic agents; anti-proliferativeagents such as enoxaprin, angiopeptin, or monoclonal antibodies capableof blocking smooth muscle cell proliferation, hirudin, andacetylsalicylic acid; anti-inflammatory agents such as dexamethasone,prednisolone, corticosterone, budesonide, estrogen, sulfasalazine, andmesalamine; antineoplastic/antiproliferative/anti-mitotic agents such aspaclitaxel, 5-fluorouracil, cisplatin, vinblastine, vincristine,epothilones, endostatin, angiostatin and thymidine kinase inhibitors;anesthetic agents such as lidocaine, bupivacaine, and ropivacaine;anti-coagulants such as D-Phe-Arg chloromethyl keton, and RGDpeptide-containing compound, heparin, antithrombin compounds, plateletreceptor antagonists, anti-thrombin antibodies, antiplatelet receptorantibodies, aspirin, prostaglandin inhibitors, platelet inhibitors andtick antiplatelet factors; vascular cell growth promoters such as growthfactors, growth factor receptor antagonists, transcriptional activators,and translational promotors; vascular cell growth inhibitors such asgrowth factor inhibitors, growth factor receptor antagonists,transcriptional repressors, translational repressors, replicationinhibitors, inhibitory antibodies, antibodies directly against growthfactors, bifunctional molecules consisting of a growth factor and acytotoxin, bifunctional molecules consisting of an antibody and acytotoxin; cholesterol-lowering agents; vasodilating agents; agentswhich interfere with endogenous vasoactive mechanisms, and combinationsthereof. These and other compounds are applied to the device.

[0086] Polynucleotide sequences useful in practice of the inventioninclude DNA or RNA sequences having a therapeutic effect after beingtaken up by a cell. Examples of therapeutic polynucleotides includeanti-sense DNA and RNA; DNA coding for endogenous molecules. Thepolynucleotides of the invention can also code for therapeuticpolypeptides. A polypeptide is understood to be any translationproduction of a polynucleotide regardless of size, and whetherglycosylated or not. Therapeutic polypeptides include as a primaryexample, those polypeptides that can compensate for defective ordeficient species in an animal, or those that act through toxic effectsto limit or remove harmful cells from the body. In addition, thepolypeptides or proteins that can be incorporated into the polymercoating 130, or whose DNA can be incorporated, include withoutlimitation, proteins competent to induce angiogenesis, including factorssuch as, without limitation, acidic and basic fibroblast growth factors,vascular endothelial growth factor (including VEGF-2, VEGF-3, VEGF-A,VEGF-B, VEGF-C) hif-1 and other molecules competent to induce anupstream or downstream effect of an angiogenic factor; epidermal growthfactor, transforming growth factor alpha and beta, platelet-derivedendothelial growth factor, platelet-derived growth factor, tumornecrosis factor alpha, hepatocyte growth factor and insulin like growthfactor; growth factors; cell cycle inhibitors including CDK inhibitors;thymidine kinase (“TK”) and other agents useful for interfering withcell proliferation, including agents for treating malignacies; andcombinations thereof. Still other useful factors, which can be providedas polypeptides or as DNA encoding these polypeptides, includingmonocyte chemoattractant protein (“MCP-1”), and the family of bonemorphogenic proteins (“BMP's”). The known proteins include BMP-2, BMP-3,BMP-4, BMP-5, BMP-6 (Vgr-1), BMP-7 (OP-1), BMP-8, BMP-9, BMP-10, BMP-11,BMP-12, BMP-13, BMP-14, BMP-15, and BMP-16. Currently preferred BMP'sare any of BMP-2, BMP-3, BMP-4, BMP-5, BMP-6, and BMP-7. These dimericproteins can be provided as homodimers, heterodimers, or combinationsthereof, alone or together with other molecules. Alternatively or, inaddition, molecules capable of inducing an upstream or downstream effectof a BMP can be provided. Such molecules include any of the “hedgehog”proteins, or the DNA's encoding them.

[0087] In one exemplary embodiment of the present invention, the medicaldevice has recombinant nucleic acid incorporated therein, wherein therecombinant nucleic acid comprises a viral vector having linked theretoan exogenous nucleic acid sequence. “Exogenous nucleic acid sequence” isused herein to mean a sequence of nucleic acids that is exogenous to thevirus from which the vector is derived. The concentration of the viralvector, preferably an adenoviral vector, is at least about 10¹⁰ plaqueforming units (“p.f.u.”), preferably at least about 10¹¹ p.f.u.Alternatively, the concentration of the viral vector is limited by theconcentration that results in an undesirable immune response from apatient.

[0088] Treatment of vaso-occlusive coils with the described materialsmay be carried out using known methods, for example dip coating, spraycoating, wiping, vapor deposition or the like.

[0089] The devices that are treated according to the procedure of thisinvention are often introduced to a selected site using the procedureoutlined below. This procedure may be used in treating a variety ofmaladies. For instance, in treatment of an aneurysm, the aneurysm itselfmay be filled with the devices made according to the procedure specifiedhere. Shortly after the devices are placed within the aneurysm, athrombus begins to form and, at some later time, is at least partiallyreplaced by cellular material formed around the vaso-occlusive devices.

[0090] In general, a selected site is reached through the vascularsystem using a collection of specifically chosen catheters and guidewires. It is clear that should the aneurysm be in a remote site, e.g.,in the brain, methods of reaching this site are somewhat limited. Onewidely accepted procedure is found in U.S. Pat. No. 4,994,069 toRitchart, et al. It utilizes a fine endovascular catheter such as foundin U.S. Pat. No. 4,739,768, to Engelson. First of all, a large catheteris introduced through an entry site in the vasculature. Typically, thiswould be through a femoral artery in the groin. Other entry sitessometimes chosen are found in the neck and are in general well known byphysicians who practice this type of medicine. Once the introducer is inplace, a guiding catheter is then used to provide a safe passageway fromthe entry site to a region near the site to be treated. For instance, intreating a site in the human brain, a guiding catheter would be chosenwhich would extend from the entry site at the femoral artery, up throughthe large arteries extending to the heart, around the heart through theaortic arch, and downstream through one of the arteries extending fromthe upper side of the aorta. A guidewire and neurovascular catheter suchas that described in the Engelson patent are then placed through theguiding catheter as a unit. Once the tip of the guidewire reaches theend of the guiding catheter, it is then extended using fluoroscopy bythe physician to the site to be treated using the vaso-occlusive devicesof this invention. During the trip between the treatment site and theguide catheter tip, the guidewire is advanced for a distance and theneurovascular catheter follows. Once both the distal tip of theneurovascular catheter and the guidewire have reached the treatmentsite, and the distal tip of that catheter is appropriately situated,e.g., within the mouth of an aneurysm to be treated, the guidewire isthen withdrawn. The neurovascular catheter then has an open lumen to theoutside of the body. The devices of this invention are then pushedthrough the lumen to the treatment site. They are held in placevariously because of their shape, size, or volume. These concepts aredescribed in the Ritchart et al. patent as well as others. Once thevaso-occlusive devices are situated in the vascular site, the embolismforms.

[0091]FIGS. 10 and 11 are end view illustrations of particular lateralprotrusions 205, in accordance with illustrative embodiments of thepresent invention. Any of the lateral protrusions 205 described inrelation to other embodiments of the present invention couldillustratively be configured similar to the FIG. 10 or FIG. 11embodiments described below. The same reference numerals are used inFIGS. 10 and 11 for elements that are the same or similar to thoseelements illustrated and described in relation to previous embodimentsand previous Figures.

[0092] Lateral protrusion 205, in both FIG. 10 and FIG. 11, includes aninterior wire 610 having an attached marker coil 400. Details pertainingto marker coil 400 were described in relation to FIG. 4. It should benoted that marker coil 400 is an optional element.

[0093] In FIG. 10, a cylindrical helical coil 1300 is disposed about aportion of wire 610 that is not covered by marker coil 400. In FIG. 11,a cylindrical helical coil 1305 is similarly configured. It should benoted that either coil could take a non-helical configuration withoutdeparting from the scope of the present invention. While FIGS. 10 and 11illustratively depict all of wire 610 covered either by marker coil 400or coils 1300 or 1305, some portions of wire 610 could, in accordancewith one embodiment of the present invention, be exposed. In accordancewith another embodiment, marker coil 400 could be eliminated and coil1300 or coil 1305 could extend around all or any portion of wire 610.Illustratively, multiple coils 1300 or multiple coils 1305 could beattached to a single wire 610 in place of a single continuous coil 1300or a single continuous coil 1305.

[0094] As is depicted in both FIG. 10 and FIG. 11, wire 610 includesfirst and second ends that are fixedly secured between inner coil 410and outer coil 405 of bridge subassembly 202. With this arrangement,coils 1300 and 1305 can be secured and maintained on their respectivewires 610.

[0095] Illustratively, coils 1300 and 1305 may be made of any of a widevariety of biocompatible metals or polymers or carbon. In particular,the metals may be selected from gold, rhenium, platinum, palladium,rhodium, ruthenium, various stainless steels, tungsten, and theiralloys, titanium/nickel alloys particularly nitinol type alloys. Inaccordance with one embodiment, coils 1300 and 1305 are flexiblyconstructed so as to accommodate delivery of subassembly 202 through atubular delivery device.

[0096] In accordance with one embodiment, subassembly 202 may beequipped with a broad range of bioactive and/or therapeutic capabilitiessimply by attaching a coil, having attached bioactive and/or therapeuticmaterial, to wire 610.

[0097] With reference to FIG. 10, in accordance with one embodiment, atherapeutic agent may be attached to coil 1300, and then coil 1300 canbe placed over wire 610. The first and second ends of wire 610 can thenbe secured between coils 405 and 410.

[0098] In accordance with one embodiment, coil 1300 in FIG. 10 issimilar to any of the coil-like vaso-occlusive device embodimentsdescribed above in relation to FIGS. 8 and 9. It should be noted,however, that for the FIG. 8 and FIG. 9 vaso-occlusive deviceembodiments to be incorporated as a coil 1300 in FIG. 10, tips 1104(FIG. 8) require modification to include a hollow opening that enableswire 610 (FIG. 10) to extend there through.

[0099] In accordance with one embodiment, at least one element in theform of a fiber is attached to coil 1300. A single, a multiplicity, oreven tufts of fibers may illustratively be attached to coil 1300. Thefibers could be attached using a variety of methods, including tying thefibers to the coil, securing tufts or bundles of fibers between openingsin the coil, etc.

[0100] Illustratively, the fibers attached to, or otherwise disposed on,coil 1300 may comprise polymeric occlusion-causing material,thrombogenic material, and/or fibrogenic material. In accordance withanother embodiment, the fibers comprise biodegradable material, such as(but not limited to) polyglycolic acid, polylactic acid, reconstitutedcollagen, poly-p-dioxanone, and their copolymers. Mixtures of thesesorts of material may also be used. In addition, the fibers may compriseany of the materials discussed above in relation to materials forincorporation into outer coating 1206 (FIG. 8) of vaso-occlusive device1100.

[0101] Referring to FIG. 11, in accordance with an embodiment of thepresent invention, fibers, having any of the above-mentionedcompositions, could be woven or braided into a fiberous woven or braidedtubular member 1310. Member 1310 may be suitably woven to enable acoaxial extension over at least one portion of coil 1305. Member 1310 isintended to illustrate another way in which fibers or a fiberousmaterial having a broad range of therapeutic properties could beattached to a coil that is attachable to a wire 610 portion of asubassembly 202. In accordance with another embodiment, rather than awoven or braided member, tubular member 1310 could take other tubularmember configurations. For example, it could be a substantiallycontinuous (substantially without gaps or openings) tube of materialthat coaxially extends over at least one portion of coil 1305.Alternatively, it could be a somewhat continuous tubular member but withholes or slits. These and other tubular member configurations couldincorporate material having characteristics similar to those describedabove in relation to other embodiments. For instance, a given tube ofmaterial could incorporate a therapeutic agent, be biodegradable, and/orbe constructed of a material for encouraging a cellular response. In oneembodiment, material could be sprayed or dip coated on a portion of coil1305.

[0102] Although the present invention has been described with referenceto preferred embodiments, workers skilled in the art will recognize thatchanges may be made in form and detail without departing from the spiritand scope of the invention.

What is claimed is:
 1. An implantable medical device for at leastpartially obstructing a neck portion of a vascular aneurysm, comprising:an occlusion subassembly comprising a central member and at least onelateral protrusion fixedly attached to the central member, said at leastone lateral protrusion and the central member being of a size andoverall flexibility to lodge at the neck portion of the vascularaneurysm; and a coil attached to the lateral protrusion.
 2. Theimplantable medical device of claim 1, further comprising a therapeuticagent disposed on at least one portion of the coil.
 3. The implantablemedical device of claim 2, wherein the therapeutic agent comprises abiodegradable material.
 4. The implantable medical device of claim 3,wherein the therapeutic agent takes the form of a tubular member that iscoaxially disposed about at least one portion of the coil.
 5. Theimplantable medical device of claim 1, further comprising a material forencouraging a cellular response disposed on at least one portion of thecoil.
 6. The implantable medical device of claim 5, wherein the materialfor encouraging said cellular response comprises a polymeric material.7. The implantable medical device of claim 5, wherein the material forencouraging said cellular response further comprises at least oneelement in the form of a fiber.
 8. The implantable medical device ofclaim 5, wherein the material for encouraging said cellular response isfibrogenic.
 9. The implantable medical device of claim 5, wherein thematerial for encouraging said cellular response is biodegradable. 10.The implantable medical device of claim 9, wherein the material forencouraging said cellular response comprises polyglycolic acid.
 11. Theimplantable medical device of claim 9, wherein the material forencouraging said cellular response comprises polylactic acid.
 12. Theimplantable medical device of claim 9, wherein the material forencouraging said cellular response comprises a mixture of polyglycolicacid and polylactic acid.
 13. The implantable medical device of claim 9,wherein the material for encouraging the cellular response comprises acopolymer of polyglycolic acid and polylactic acid.
 14. The implantablemedical device of claim 7, wherein said at least one element in the formof a fiber is a multiplicity of elements in the form of fibers.
 15. Theimplantable medical device of claim 14, wherein the multiplicity ofelements in the form of fibers comprise a biodegradable material. 16.The implantable medical device of claim 7, wherein said at least oneelement in the form of a fiber is a bundle of individual fiber strands.17. The implantable medical device of claim 16, wherein the bundle ofindividual fiber strands comprises a biodegradable material.
 18. Theimplantable medical device of claim 1, further comprising a fiberouswoven tubular member extending coaxially about at least one portion ofthe coil.
 19. The implantable medical device of claim 18, wherein thefiberous woven tubular member comprises a material for encouraging acellular response and that is biodegradable.
 20. The implantable medicaldevice of claim 19, wherein the fiberous woven tubular member isbraided.
 21. An implantable medical device, comprising: a loop of wirehaving first and second ends connected to a base member; a coil radiallydisposed about a portion of the loop of wire; and a material forencouraging a cellular response disposed on at least one portion of thecoil, the material also being biodegradable.
 22. The implantable medicaldevice of claim 21, wherein the material takes the form of a tubularmember disposed on at least one portion of the coil.
 23. The implantablemedical device of claim 21, wherein the material is sprayed on at leastone portion of the coil.
 24. The implantable medical device of claim 21,wherein the material is dip coated on at least one portion of the coil.25. The implantable medical device of claim 21, further comprising amarker coil radially disposed about a portion of the loop of wire. 26.The implantable medical device of claim 21, wherein the material forencouraging said cellular response comprises polyglycolic acid.
 27. Theimplantable medical device of claim 21, wherein the material forencouraging said cellular response comprises polylactic acid.
 28. Theimplantable medical device of claim 21, wherein the material forencouraging said cellular response comprises a mixture of polyglycolicacid and polylactic acid.
 29. The implantable medical device of claim21, wherein the material for encouraging said cellular responsecomprises a copolymer of polyglycolic acid and polylactic acid.
 30. Animplantable medical device, comprising: a loop of wire having first andsecond ends connected to a base member; a coil radially disposed about aportion of the loop of wire; and a fiberous woven tubular membercoaxially engaging at least one portion of the coil.
 31. The implantablemedical device of claim 30, wherein the fiberous woven tubular membercomprises a material for encouraging a cellular response and that isbiodegradable.
 32. The implantable medical device of claim 31, whereinthe material for encouraging said cellular response comprisespolyglycolic acid.
 33. The implantable medical device of claim 30,wherein the material for encouraging said cellular response comprisespolylactic acid.
 34. The implantable medical device of claim 31, whereinthe material for encouraging said cellular response comprises a mixtureof polyglycolic and polylactic acid.
 35. The implantable medical deviceof claim 31, wherein the material for encouraging said cellular responsecomprises a copolymer of polyglycolic and polylactic acid.